BFF Control Loader (Force
The BFF Control Loader software runs
with FS9/X and X-Plane flight simulators to generate force
demands for DIY FFB flight controls. It provides outputs
compatible with the CL_SPU +
brushless motor drivers available on the site.
BFF Control Loader Quick Start Guide
BFF Control Loader Software
To unlock the software on a specified PC you must run the
software then follow the registration prompts and email your
PC ID to me. I can then send you the unlock key for that PC.
The software will run
unregistered in DEMO mode - the force output
will release after 10 minutes of running
A non-commercial home-use licence is included with the price of
CL_SPU + BLDRV2-24 card orders. For commercial use
registration of the software please contact me.
New Configuration Manager
UPDATE AUGUST 2015:
Version V1.3 includes a new Configuration Manager
which brings all the system settings under a single set up
Once installed please use the IMPORT button in
the Configuration Manager to import your existing CL system
More details in the
On-Line User Guide.
UPDATE JULY 2014:
Version V1.122 of the CL software adds portable
USB Dongle licensing.
The USB dongle allows a software registration to
operate on any PC the dongle is plugged into. With the normal
non-portable registration your unlock key works only on your specified PC.
For more details click on the Dongle image on the
For FS9/X you will need an
up-to-date version of Pete Dowson's FSUIPC
installed. And for use with X-Plane 9.6+ & v10 you
will need to install Torsten Spiering's XPUIPC
v1.9.0 or later. For both see links to the
(Many thanks to Torsten
Spiering for the use of XPUIPC.)
The CL system was developed principally for
leisure simulators with GA aircraft behaviours. The flight
control forces simulated by the BFF CL Software include:
aerodynamic loading (returning forces proportional to control
surface displacement and airspeed)
Adjustable aerodynamic force gains
(equivalent to adjustable control surface area)
Angle of attack (alpha and beta)
effects (eg for longitudinal stability response)
Realistic GA trim behaviour (independent
of simulator trim system, controls can be trimmed in any
position) using trim potentiometers or trim
Control surface static & dynamic
weight effects (aircraft acceleration effects)
Engine vibrations (vary with power &
Runway vibration effects (vary with
Stall buffeting effects (frequency
and amplitude definable - eg stick vibration type
Damping and friction adjustments (-ve
Auto Pilot following (native sim AP only - when used with
CL_SPU + BLDRV2-24
Separate configuration program with saveable
NEW for V1.120 -
helicopter cyclic trim loading mode.
NEW for V1.210 -
Heavy Jet mode.
NEW for V1.3 - Configuration Manager, support for
ProSim, and also
Failure Mode Loading.
used with the CL_SPU + BLDRV2-24 brushless motor drivers the CL
software exports flight simulator dependent force components
at approximately 75Hz. These are added to the force
components calculated onboard the BLDRV2-24 card at 500Hz.
The on-board force processing of the BLDRV2-24 allows the
CL software to run with minimal system resource which allows
it to run on the same PC as the flight sim.
The included Configuration Manager
application allows the
configuration settings to be adjusted and saved in
configuration files and to be updated in the main CL
software as it runs. This allows the force effects to be
tuned with the FFB active.
Control Loading Model
The loading calculation model has been
developed to provide effective force demands for low cost
DIY systems (compared to commercial control loader systems)
and is principally based on the behaviour of GA aircraft
with reversible controls.
The model uses control axis
position and velocity as the indicator of control surface
position and velocity, this is measured at the brushless
motor quadrature encoder. Airspeed, aircraft AoA,
accelerations, engine condition, runway speed, stall state
and other dynamic flight data are all
taken live from the flight sim (FS9/X or X-Plane). Trim surface position is taken from the
independent trim pot positions or trim button/switch
Aerodynamic loads are
calculated from control surface deflection and aircraft AoA and airspeed.
The airspeed exponent used in the calculation of control
surface lift can be adjusted to suit different control
types. For small aircraft with controls mechanically
connected to the control surfaces airspeed squared can be
set. For fly-by-wire systems a linear relationship can be
set (stiffness varies linearly with airspeed).
The model allows control forces to be
calculated without the need to monitor applied loading and
this greatly reduces the complexity and cost for DIY systems
by avoiding the need for force sensors in the controls.
For Auto Pilot following the CL_SPU +
cards switch automatically into a PID controlled position
following mode and the CL software generates position
demands based on the AP control actions read from the flight
sim. The AP following can be disengaged by moving the
controls or by the usual sim instruments.
AP following can be disabled if not required.
Note that the AP following functionality is active for the
simulator software's native AP system only - not for
external AP packages. UPDATE - AP following for Sim-A and
Pro Sim are now also available in the recent software
To operate effectively the software must be
used in a properly designed and built system as described on
the BLDRV2-24 page. The
quality of the force feedback you obtain will be critically
dependent on the quality of the design and build of the force
transmission and other mechanical elements in your controls.
The previous CL Software web page and
versions is here.
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copyrighted, If you'd like more information or have any
comments please contact me at